We study systems with a finite number of degrees of freedom, or a finite volume with a well defined boundary.

Our focus is the dynamics of such systems interacting with the environment which can be a material environment (ultracold gases, quantum aggregates, clusters etc.), radiation from advanced light sources, or noise, to give a few examples. Our theoretical tools range from traditional quantum methods over novel semiclassical approaches to classical concepts of nonlinear dynamics.

We are interested in cooporate and collective phenomena in such systems which emerge under extreme conditions, e.g., a cold environment or fast excitation.

Key topics include Rydberg dynamics in cold gases, long-range chemical binding, attosecond dynamics in atoms, molecules, clusters and plasmas, and the response of such systems to short X-ray pulses as avaiable from free electron lasers.